Vue Router - 如何在router.beforeEach（）中停止无限循环

Question

我这里有这段代码。

Router.beforeEach((to, from, next) => {
    // AUTH = firebase.auth()
    // it allows me to get the auth 
    // status of the user
    AUTH.onAuthStateChanged(user => {
        if (to.matched.some(m => m.meta.auth) && user) {
            // I am checking if it is the user's first
            // time to login so I can mandatory redirect 
            // them to the setup page.
            isFirstLogin().then(firstLogin => {
                if (firstLogin) {
                    next({ name: 'first-login' }) // this causes infinite loop
                } else {
                    next()
                }
            });
        } else {
            next({ name: 'logout' }); // this causes infinite loop
        }
    })
})

然而，这一行next({ name: 'first-login' })会导致无限循环。

如何防止这种情况？感谢。